1. Field of the Invention
The invention relates to a power control method for a battery, and more particularly, to a power control method for a battery capable of reducing power consumption when the battery is stored.
2. Description of the Prior Art
Considering the convenience of using an electronic system and the capacity requirement of the power supply, most electronic systems adapt rechargeable battery as the source of its power supply, in which the batteries using lithium polymer as core substance are regarded as the most mature products with high capacity density specification. Generally, when a rechargeable battery leaves factory, it should go through some preliminary tests through insertion on an electronic system such as a notebook computer for checking its functionality before the electronic system is shutdown. However, even as the rechargeable battery is installed on a shutdown electronic system, there will still be tiny amount of power consumption, due to the existence of circuits between the rechargeable battery and the electronic system. All the power consumption is caused by the unopened circuits.
A rechargeable battery usually has charge capacity of 40% of its full charge capacity (FCC) when leaving factory. As mentioned, after the rechargeable battery leaves the factory, it needs to go through some tests before set to shutdown to wait for transportation, stocked for a certain period of time, and finally shipped to a user who purchased it. During these stages, the capacity of the rechargeable battery is kept consumed. Overly discharging phenomenon may cause unrecoverable damage to the battery once the battery takes too long in transportation and stock.
While some power saving techniques are implemented in the rechargeable battery according to the prior art, these techniques simply use some sleep modes defined by the rechargeable battery, i.e., when the rechargeable battery has power consumption lower than a specific value like 20 mA for over a specific time like 30 seconds, it is set in the sleep mode, and the rechargeable battery does not provide power for the electronic system. The rechargeable battery in such sleep mode, however, still has closed circuit between the battery and the electronic system, which means tiny amount of power consumption still occurs.